Related papers: Rapid Evolution of the White Dwarf Pulsar AR Scorp…
AR Scorpii (AR Sco) is a binary star system containing the only known white dwarf (WD) pulsar. Previously reported photometric datasets only provide coverage back to 2005, but we extend the observational baseline for AR Sco back to the…
We explore the possibility that the recently discovered white dwarf pulsar AR Sco acquired its high spin and magnetic field due to repeated episodes of accretion and spin-down. An accreting white dwarf can lead to a larger mass and…
We analyze long-cadence Kepler K2 observations of AR Sco from 2014, along with survey photometry obtained between 2005 and 2016 by the Catalina Real-Time Sky Survey and the All-Sky Automated Survey for Supernovae. The K2 data show the…
The discovery of the white dwarf binary system AR Scorpii (AR Sco) with its fascinating non-thermal dominated multi-frequency emission has sparked renewed interest in potential high energy gamma-ray emission from white dwarf pulsars. The…
The emission of the white dwarf-M dwarf binary AR Sco is driven by the rapid synchronization of its white dwarf, rather than by accretion. This requires a comparatively large magnetic field $\sim 100$ gauss at the M dwarf and $\sim 10^8$…
The binary system AR Scorpii hosts an M-type main sequence cool star orbiting around a magnetic white dwarf in the Milky Way Galaxy. The broadband non-thermal emission over radio, optical and X-ray wavebands observed from AR Scorpii…
Taking advantage of the very precise de Jager et al. optical white dwarf orbit and spin ephemerides; ASCA, XMMN, and Chandra X-ray observations spread over 10 yrs; and a cumulative 27 yr baseline, we have found that in recent years the…
We apply the standard radio pulsar rotating vector model to the white dwarf pulsar AR Sco's optical polarization position angle swings folded at the white dwarf's spin period as obtained by Buckley et al. (2017). Owing to the long duty…
White dwarfs (WDs) are the most abundant compact objects, and recent surveys have suggested that over a third of WDs in accreting binaries host a strong (B $\gtrsim$ 1 MG) magnetic field. However, the origin and evolution of WD magnetism…
We present optical photometry, spectroscopy and photopolarimetry, as well as ASCA X-ray observations, of the recently discovered intermediate polar 1WGA J1958.2+3232. Through the first detection of an optical beat frequency, we confirm the…
In view of the new recent observation and measurement of the rotating and highly-magnetized white dwarf AR Scorpii \cite{Marsh:2016uhc}, we determine bounds of its moment of inertia, magnetic fields and radius. Moreover, we investigate the…
Eleven seasons, from 2004 to 2014, of photometric monitoring of the intermediate polar AO Psc are presented and are compared with previous observations. The spin up of the white dwarf is found to be slowing down. The amplitudes of the…
We consider the evolution of white dwarfs with compact object companions (specifically black holes with masses up to 10^6 solar masses, neutron stars, and other white dwarfs). We suppose that the orbits are initially quite elliptical and…
The compact object in the interacting binary AR Sco has widely been presumed to be a rapidly rotating, magnetized white dwarf (WD), but it has never been detected directly. Isolating its spectrum has proven difficult because the spin-down…
We report the first result from our survey of rapid variability in symbiotic binaries: the discovery of a persistent oscillation at P=1682.6 +- 0.6 s in the optical emission from the prototype symbiotic, Z Andromedae. The oscillation was…
FO Aqr is a bright intermediate polar that has long displayed large amplitude photometric variations corresponding to the 20.9 min spin period of its white dwarf. Between 2016 and 2020, the system suffered a series of unprecedented…
Simulation of Doppler H-alpha tomogram of the nova-like star AE Aquarii suggests that the dipole magnetic moment of the white dwarf is close to 1.5E+34 G cm^3. This is consistent with the lower limit to the magnetic field strength of the…
From 1979 to 2001, the magnetic axis of the white dwarf in the polar DP Leo slowly rotated by 50 deg in azimuth, possibly indicating a small asynchronism between the rotational and orbital periods of the magnetic white dwarf. We have…
The distribution of white dwarf rotation periods provides a means for constraining angular momentum evolution during the late stages of stellar evolution, as well as insight into the physics and remnants of double degenerate mergers.…
Axions are the natural consequence of the introduction of the Peccei-Quinn symmetry to solve the strong CP problem. All the efforts to detect such elusive particles have failed up to now. Nevertheless, it has been recently shown that the…